638462889 has 6 divisors (see below), whose sum is σ = 922224186. Its totient is φ = 425641920.

The previous prime is 638462879. The next prime is 638462893. The reversal of 638462889 is 988264836.

638462889 is a `hidden beast` number, since 6 + 3 + 8 + 4 + 628 + 8 + 9 = 666.

It can be written as a sum of positive squares in only one way, i.e., 389075625 + 249387264 = 19725^2 + 15792^2 .

It is not a de Polignac number, because 638462889 - 2⁴ = 638462873 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (638462879) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 35470152 + ... + 35470169.

It is an arithmetic number, because the mean of its divisors is an integer number (153704031).

Almost surely, 2^638462889 is an apocalyptic number.

It is an amenable number.

638462889 is a deficient number, since it is larger than the sum of its proper divisors (283761297).

638462889 is a wasteful number, since it uses less digits than its factorization.

638462889 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 70940327 (or 70940324 counting only the distinct ones).

The product of its digits is 3981312, while the sum is 54.

The square root of 638462889 is about 25267.8231947273. The cubic root of 638462889 is about 861.0834051785.

The spelling of 638462889 in words is "six hundred thirty-eight million, four hundred sixty-two thousand, eight hundred eighty-nine".